Germishuys, R. and Diamond, R. 2022. Nitrogen isotopes of Eichhornia crassipes (water hyacinth) confirm sewage as leading source of pollution in Hartbeespoort Reservoir, South Africa. South African Journal of Science. 118, 7/8 (Jul. 2022). DOI:https://doi.org/10.17159/sajs.2022/11098.